Detection and Estimation of Improper Complex Random Signals

IEEE Trans. Wireless Commun.

Vucetic

et al. 2010

This letter derives mathematical expressions for the received signal-to-interference-plus-noise ratio (SINR) of uplink Single Carrier (SC) Frequency Division Multiple Access (FDMA) multiuser MIMO systems. An improved frequency domain receiver algorithm is derived for the studied systems, and is shown to be significantly superior to the conventional linear MMSE based receiver in terms of SINR and bit error rate (BER) performance. KeywordsSC-FDMA, Multiple-Input Multiple-Output (MIMO), 3GPP LTE uplink.

Section: Improved Frequency Domain Receiver Algorithmmentioning

confidence: 99%

Analysis of receiver algorithms for lte LTE SC-FDMA based uplink MIMO systems

Lin

IEEE Trans. Wireless Commun.

Vucetic

et al. 2010

“…For a complex random vector r, its second-order statistics are completely characterized by its autocorrelation matrix C rr = E[rr ℋ ] as well as the pseudo-autocorrelation matrix C rr = E[rr ] [19]. Most existing studies on receiver algorithms (including the one presented previously in Section III-A) only exploit the information contained in the autocorrelation function of the observed signal.…”

Section: B Improved Blind Mmse Detectormentioning

confidence: 99%

Enhanced subspaced approach to interference mitigation

2011 11th International Symposium on Communications &Amp; Information Technologies (ISCIT)

Yin

Tafazolli

et al. 2011

Abstract-In this paper, we study an enhanced subspace based approach for the mitigation of multiple access interference (MAI) in direct-sequence code-division multiple-access (DS-CDMA) systems over frequency-selective channels. Blind multiuser detection based on signal subspace estimation is of special interest in mitigating MAI in CDMA systems since it is impractical to assume perfect knowledge of parameters such as spreading codes, time delays and amplitudes of all the users in a rapidly changing mobile environment. We develop a new blind multiuser detection scheme which only needs the priori knowledge of the signature waveform and timing of the user of interest. By exploiting the improper nature of multiple access interference (MAI) and intersymbol interference (ISI), the enhanced detector shows clear superiority to the conventional subspace-based blind multiuser detector. The performance advantages are shown to be more obvious in heavily loaded systems when the number of active users is large.

“…The second-order properties of a complex random process are completely characterized by its autocorrelation function as well as the pseudo-autocorrelation function [10]. Most existing studies on receiver algorithms only exploit the information contained in the autocorrelation function of the observed signal.…”

Section: Introductionmentioning

confidence: 99%

“…Such a scenario arises when transmitting symbols with improper modulation formats (e.g., ASK and OQPSK) over complex channels. It was shown in Schreier et al [10] that the performance gain of WLP compared to conventional processing in terms of mean square error can be as large as a factor of 2. MIMO transceiver design was considered in Mattera et al [13], Sterle [14], where it was shown that when channel information is available both at the transmitter and receiver, joint design of the precoder and decoder using WLP yields considerable performance gains at the expense of a limited increase in the computational complexity, compared to the conventional linear transceiver in the scenario where real-valued symbols are transmitted over complex channels.…”

Section: Introductionmentioning

confidence: 99%

Frequency-domain equalization for OFDMA-based multiuser MIMO systems with improper modulation schemes

EURASIP J. Adv. Signal Process.

Lin

Fagan

et al. 2011

In this paper, we propose a novel transceiver structure for orthogonal frequency division multiple access-based uplink multiuser multiple-input multiple-output systems. The numerical results show that the proposed frequencydomain equalization schemes significantly outperform conventional linear minimum mean square error-based equalizers in terms of bit error rate performance with moderate increase in computational complexity.